Significant challenges prevent conventional wind turbine (Horizontal Axis Wind Turbine (HAWT) derived power from replacing fossil fuels used for production of electricity and hydrogen from electrolysis of water. At the end of 2013 there were more U.S. wind power megawatts (MW) under construction than ever in history: Over 12,000 MW of new generating capacity was under construction, with a record-breaking 10,900 MW starting construction activity during the fourth quarter. The wind projects under construction could power the equivalent of 3.5 million American homes, or all the households in Iowa, Oklahoma and Kansas. (ref. http://www.awea.org/MediaCenter/pressrelease.aspx?ItemNumber=60440)
The majority of this growth has been in the form of conventional, horizontal-axis wind turbines (HAWT). Converting the kinetic energy of the wind into useful electricity requires converting the linear horizontal motion of wind into the rotational motion of a shaft in an electrical generator. In every case this requires some method of maintaining a static force against the motion of the wind, to keep the wind-collection apparatus from simply blowing away. Conventional wind turbines accomplish this by mounting rotors rigidly on towers, relatively close to the ground. This arrangement works reliably, but is relatively expensive, requires large amounts of structural material, hard to maintain and operate (due in large to the height of the generator), and cannot tap the much stronger winds often present at higher altitudes (ref. 2 http://en.wikipedia.org/wiki/Kite_enemy).
The key to making wind energy more efficient is to access high altitude wind. “Turbines in conventional machines are located at heights ranging from 100 m to 200 m; however, wind flow is more consistent and faster at altitudes above 500 m. Therefore, winds at this altitude could act as a reliable source of energy that can be harnessed using kites, buoyant turbines and sails. “High Altitude Wind Power (HAWP), has the potential to replace a high percentage of the power generated from fossil fuels and traditional Horizontal Axis Wind Turbines (HAWT)”. (ref. http://www.modernpowersystems.com/news/newshigh-altitude-wind-power-generation-is-now-on-the-map-4795780.
Achieving these heights require close coordination with Federal, State and local authorities having jurisdiction of air space over land and water that may adversely effect air travel and public safety especially over urban areas over the United States and territorial waters. Current regulations are covered under Federal Aviation Administration (FAA) regulation PART 101—MOORED BALLOONS, KITES, AMATEUR ROCKETS AND UNMANNED FREE BALLOONS Subpart A—General Sec. 101.1 Applicability. 101.3 Waivers. 101.5 Operations in prohibited or restricted areas. 101.7 Hazardous operations. Subpart B—Moored Balloons and Kites 101.11 Applicability. 101.13 Operating limitations. 101.15 Notice requirements. 101.17 Lighting and marking requirements. 101.19 Rapid deflation device (ref. https://www.gpo.gov/fdss/pkg/CFR-2012-title14-vol2/pdf/CFR-2012-title14-vol2-part101.pdf) provides regulatory controls for aerostats over land and U.S. territorial oceans. Additional restrictions are recommended between outer space—which is not subject to national jurisdiction—and national airspace), with suggestions ranging from about 30 km (19 mi) (the extent of the highest aircraft and balloons) to about 160 km (99 mi) (the lowest extent of short-term stable orbits). The Fédération Aéronautique Internationale has established the Kármán line, at an altitude of 100 km (62 mi), as the boundary between the Earth's atmosphere and outer space, while the United States considers anyone who has flown above 50 miles (80 km) to be an astronaut; indeed descending space shuttles have flown closer than 80 km (50 mi) over other nations, such as Canada, without requesting permission first.[5] Nonetheless both the Kármán line and the U.S. definition are merely working benchmarks, without any real legal authority over matters of national sovereignty (ref. https://en.wikipedia.org/wiki/Airspace).
Eliminating rotating blades and related components will significantly lower the capital costs of HAWT and allow the generator to be located at ground level for ease of maintenance and operation. “An analysis recently published in Windpower Endineering and Development gives us a rough idea of how to cut capital costs of generating electricity from wind energy. While the report focuses on how improvements to drive trains can increase efficiency, it also breaks down the cost proportion of different parts of the turbine. The large metal components (tower, nacelle, and blades) account for nearly 80 percent of the cost of a typical turbine. Also, about 65 percent of the cost of an on-shore wind farm is the capital expense of the turbines themselves. That means the cost of wind energy is largely determined by the cost of these big castings.”
In addition, eliminating the need of a power grid will allow a greater use of wind energy especially in areas remote from power transmission lines. “Even as China races ahead of other countries in terms of installed wind capacity, its turbines aren't producing electricity at the same rate because of inadequate transmission infrastructure. Even with more than double the installed capacity as the U.S., China generated only 241 TWh of wind power compared with 224 TWh, according to data from China's National Energy Administration and the U.S. Energy Information Administration showing generation over 12-months ending in the fourth quarter.” (ref. http://www.renewableenergyworld.com/articles/2016/08.html.